# dots on maps

[Steven Clemants]

My problems with vouchers/non-vouchers are based partly on Neil's comments
about shot-guns but more importantly on several other thoughts.

First.  In my studies of the flora around New York Metropolitan region I
have accumulated about a 1000 recent records of Red Maple.  I know of no
herbarium that would want 1000 specimens of red maple from NYC region.  I
have, however, collected about 75 vouchers from throughout the region and
they provide a basis checking the validity of the non-vouchered reports.

Second.  I know there are a lot of people who would like to make a
contribution (we have enlisted over 250 volunteers) but either do not know
how to make vouchers or we may not want them making vouchers.  We need to
have them contribute and be a part of Biodiversity studies.  We do not need
to set up an elite system where the only data we will use is data based on
vouchers and the only people qualified to collect vouchers are scientists
with Ph.D.'s.

What I mean by the last sentence (below) is that I do not rely solely upon
unvouchered material.  For the New York Metropolitan Flora I do not consider
a species a part of the flora unless there are vouchers.  Comparing the
total distribution against only vouchered distribution allows me to tell if
there is a great deal of disparity and to re-examine some non-vouchered
records or eliminate them from the map (with notes in the text to that
effect).

As to scalability of gridded data it depends upon the grid size and the
accuracy of the underlying data.  Much of the older specimens we use have
very vague location data (anywhere within probably 2-4 km of a village).  By
putting a dot on the map you suggest that you have more detailed data.
Obviously the data we are collected now is accurate to within a few hundred
meters.

Steven Clemants
Director of Science
Brooklyn Botanic Garden
1000 Washington Ave.
Brooklyn, NY 11225
(718) 623-7309
----- Original Message -----
From: Dr. Neil Snow <nsnow at bentley.unco.edu>
To: Steven Clemants <steveclemants at BBG.ORG>
Cc: <TAXACOM at USOBI.ORG>
Sent: Wednesday, November 03, 1999 6:53 PM
Subject: Re: # dots on maps


> Steven's disagreement about the need for vouchers is probably influenced
by the
> fact that the collecting of ornithological vouchers (see his reference to
> Breeding Bird Atlas) is far more problematic than collecting insects,
plants, or
> many other taxa.  Shotguns generally are not easily carried about,
particularly
> overseas.  (I realize mist nets are used as well.)
>
> Why vouchers?  Because many of us place no weight whatsoever on
non-documented
> (unvouchered) reports.  Vouchers allow repeatability.  They serve a lot of
other
> purposes as well (see Snow & Keating in Cons. Biology 13: 943-944.)
>
> Also,  Steven may wish to clarify his last sentence, which begins "I think
that
> observations....."?
>
> NS
>
> Steven Clemants wrote:
>
> > I have found that using a grid pattern, such as the breeding bird atlas,
> > allows one to see distribution patterns better.  There is less build up
of
> > dots over university sites.
> >
> > I must disagree about the need for vouchers.  Vouchers are to be
preferred
> > but the Breeding Bird Atlas and other projects and phenomenally useful
even
> > though they are not based on vouchers.  I think that observations which
can
> > be referenced to vouchered distributions can fill in distributions
without
> > clogging museums and herbaria with thousands of specimens of common
species.
> >
> > Steven Clemants
> > Director of Science
> > Brooklyn Botanic Garden
> > 1000 Washington Ave.
> > Brooklyn, NY 11225
> > (718) 623-7309
>
>
>
>